"AFFINITY OF IRON FOR SULPHUR AND ITS STRENGTHENING EFFECTS.
Owing to a well-known writer having claimed that iron does not absorb sulphur, and that the founder has no need to fear its existence in castings, the author presents this chapter to prove that the contrary condition prevails. The following tests which the author made are such as can be repeated by any one who may be desirous of verifying this question:
TABLE 31—SULPHUR TEST.
No. of Test. Quality in Casting. Micrometer Measurement. Contraction. Deflection. Broke at— in Ibs. Chill. Strength per sq. inch.
18 19 Direct bar Sulph. " I. TOO 1.089 6-32 7-32 .090 .050 1385 1860 %" all. 1457 1997
TABLE 32 — CHEMICAL ANALYSIS.
No. of Test. Silicon. Sulphur. Manganese. Phosphorus.
18 19 Iron charged. Direct bar. Sulph. bar. .98 •77 .86 .015 •0/9 •175 •30 •3* •37 .092 .097 .097
Test bar No. 18 is one of four which were poured with iron direct from the cupola, with the ladle holding about 100 pounds of metal. After pouring these test bars, about 20 pounds of this metal was then poured into a hand ladle, the bottom lining of which was composed of fire clay mixed with about two andrifice of strength. Before the founder knew so much about silicon, and had good luck in mixtures, his castings would generally show a rich, dark, open fracture, making a strong, soft casting, instead of being found, as to-day with many, in a close, silvery-grained grade, making a soft, rotten, leaden casting.